Elastic suspension system for vehicles



March 29, 1927. 1,622,892Y F. l.. o. WADSWORTH .ELASTIC SUSPENSIONSYSTEM-FOR VEHICLES Filed July 1o, 1922 'sheets-Sheetl ELASTICSUSPENSION SYSTEM FOR VEHICLES Filed July 10, 1.922 v 3 Sheets-Shea?l 2kall March 29 1927.

F. L; O. WADSWORTH Ell Filed July l0l 1922 3 Sheets-Sheet 3 iatenteclMar. 29, 1927.

FRANK L. O. WADSW'GRTH, OF

PITTSBURGH, PENNSYLVANIA.

ELAS'IIC SUSPENSION SYSTEM FOR VEHICLES.

Application filed July 10,

My invention relates to that type of elastic suspension systems in whichsupplemental cushioniim devices are interposed between the ends oit' theordinary suspension springs and those parts ot the vehicle trame orchassis to which the said ends are ordinarily attached either byshackles or pintle bolts; and the generic purpose ot these improvementsis to greatly increase the shock absorbing' capacity of the sprinp;system and render the latter capable ot eilectively cushioning and:.il'isorbing the eiliect ot' both the minor vibrations and ot theshocks that are imposed on the wheel and axle members r under the widelyvarying` conditions of road travclg-thus protecting` the body of thevehicle and the occupants tliereot against the objectionableoscillations and jars to which they are subjected by the action oi" theusual form et leali spring' supports.

Another general object oi these improvements to provide a spring`suspension system which will. act eiiiciently in elastically resisting'and checking. 'not only the compre sion ot the system, but also therebound upthrow that follows such compressive movementsg-thuseliminating;` or greatly abatinp` the disagreeable and sometimesdangerous tossinal l and pitching which result 'from an unrestrainedrecoil or expano-li' the stressed suspension elements,

A further purpose of this invention is to providey a 'form of connectionor coupling between the main spring element 'ot' the system and thoseparts of the vehicle to which this primary suspension member isordinarily attached, which will prevent, or eliminateg any retlexmovement, or negative flexure, et the main spring when the body and axleparts separate, or expand, beyond the normal load position 5' and whichwill thus avoid or greatly diminish, the danger' oit' permanentlydistorting` or completely rupturing` the said primary suspension memberby an excessive or supernormal rebound stress.

Still another object of the present improvements to provide a controland actuating' mechanism for the supplemental cushioning;` device whichwill prevent the recoil or expansion or" the elastic elements thereofbeyond the initially tensione-d term assuu'ied by them under normal orstatic load conditions, but which will also enable said elastic elementsto be progressively and singly 'lleXed by movement-s of the 1922. SerialNo. 573,832.

spring' suspended parts in either direction from the positionV ot staticequilibrium. An accompanying feature ot this provision is the productionot a very compact term of supplemental suspension spring, which has avery wide range oil action in restrainingr both the abnormal approach orthe supernormal separation of the body and aXle members ot the vehiclechassis.

A more specific feature of this invention is to provide a form oit fluidpressure suspension element, or a pneumatic spring shackle support, thatcomprises a volumetrieally elastic, but permanently sealed fluidretaining cell or chamber et metal or other equivalent material which isnot detrimentally affected by the action of heat or oil, and which isnot dependent upon thev action of any packing or of any mechanical pumpfor preventing or compensating` for the leakage of the compressed fluidtherefrom.

`Another specific object ot my improvements is to provide a simple tormof highly elastic or flexible container' which is capable of arelatively large volumetric contractionand expansion with a relativelysmall clistertion of any part of the containing walls; and which willtherefore be capable of long continued use under severe conditions ofvibration and oscillation without any undue straining7 orcrystallization, or other detrimental change, in the metal or othermaterial ot' which these walls maybe composed.

Other novel features of construction and operation-which may not bespecifically pointed out in the preceding statements of invention-willbe made apparent, to those skilled in this art, by the followingdescription of certain exem ilary embodiments et my improvements.y thatare illustrated in the accompanyingr drawings, in which:

Fig. l is a general side view of one form of my improved suspensionsystem as applied to one o1 the main side leaf springs ot a vehicle;Fig. 2 is an 'enlarged longitudinal section of one form of thesupplement-al spring elements that may be used as a part ot theconstruction shown in Fig. l; Fig'. 3 is a cross section on the plane 33 of Fig. 2; Fig. fl is a partial sectional elevation, on the plane 4f-4of Fig. 3, with the parts in the position which they assume under anincreased load stress; Fig. 5 is another side view ot a secondillustrative embodiment et my present improvements; Fig. 6 is a similarview ot a portion of this afs-I same construction with the parts in theposition ol extreme rebound; Fig. 7 is an enlarged longitudinal section,similar to that of Fig. 2; ot' another term of fluid cell constructionthat may be used in this exempliiication ot the invention; Fig. 8 is anelevation; partially in section, ot the construction shown in Fig. 7;but with the parts in the position oit extreme compression; Figi-1;. 9is still another general side yiew ot a third embodinient of my presentinvention; Fig. 10 is a longitudinal section, similar to those of Figs.2 and 7, of the fluid suspension member ot this last construction; ligg.l1 is a partial longitudinal section of 'the said member with the partsthereof in the position which they occupy when subjected to abnormalkinetic load; and Fig. l2 is a detail View of an eccentric collaradjustmentthat may be used with any one ot' the exemplary forms etconstruction herein shown and described.

In the organization shown in Fig. l the inner end or the main side leatspring` l is flexibly coupled to the body oli the yehicle in the usualmanner; and the outer end of this primary suspension member isoperatively conjoined to the projectingl horn 2 ot the body sill bymeans of my supplemental suspension mechanism. This comprises a forkedlever 5 which pivotally mounted, at one end; on the laxle bracket 6; isflexibly coupled at an intermediate point of its length with the eye endet the main spring` l, by means of the solid '1.5 shaped shackle link 7;and is operatively connected; at its outer extremity; to a suitablesupjilcmental spring;r support on the body ot the Vehicle. rl`he centralportion of the lever is provided with a pair et depending` ears 8 thatextend downward, one on each side of the main leaf springl, and areconnected at the bottom by a cross bolt 9, on which is mounted aneccentric collar that can be clamped in any desired position between theears 8, 8, (as shown in detail in Fig. 1L) and is preferably so adjustedas to malte contact engagement with the under side of the primarysuspension spring` when tuey parts of the system are in the normal fullline positions7 N41@ of static equilibrium. The secondary spring'support that carries the front end ot the lever o may be ot anyappropriate form; as here shown it consists of an elastically controlledplunger which is slidably mounted in a bracket ll that is rigidlysecured to the body horn by means of the pintlc and stirrup bolts 12--12YVhen this organization is subjected to a kinetic compression stress`and the body and axle members 2 and G are tor-ced toward each other(from the full line positions N-n toward the upper dotted line positionsCi-C--c of Fig. l) the plunger l0 is raised against the supplementalspring pressure which supports and balances the normal load on the endet the body horn Q. The concurrent incrczr-e in the stre on the outerends et the relatively rigid lever 5 and theI atifely flexible mainspring' l roclfs these pivotally connected elements in a clockwisedirection (with respect to their axle supports), and carries theeccentric collar on the bolt 9 away from its engagement with the lowerleaf ot the primary suspension member; thus permitting;` the latter tohe positirely flexed and straightened out to any required degree as theload and compression strain on the system is progres- .ffiyelj-,fincreased. But when the parts have again returned to the normal loadposition l?, and are subjected to a rebound or cxpansion stress-thattends to carry them Yfrom the full line positions ot Fig'. l toward thelower dotted line positions ll-R-r of that ligure-the engagement of thecccentric collar stop on the bolt 9 with the nain spring` prevents anyrelative countercloelrwise movement ot these members on their axlesupports; and compels the interennnnjed and inter-locked elementsil--G-- 7 c-S) and l() to move downward (or away Jtrom the bot y) as arigid unit, without permitting any recoil7 or negative tlcxure of theprimary suspension spring' l. This expansion meyement is resisted by theaction et gravity, which may he assisted; it desired` by a suitablerestraint on the downward movement ot the springv controlled plunger l0in its body support ll. The supplemental lever-stop-spring suspensionmechanism described therefore permit-fy the main leali' spring` to flexfreely in one direction-under an increased compression stress Hbutprevents` it from rctlexing beyond thev term that it assumes undernormal load.

aso acts as a radius arm which nmintains tl e axle member at n fixeddistance 'from the rigid bracket support llj on the 'front horn ot thevehicle body. and thus prevents any tore and all pitching; el the twhile the trans'crse rigidity oit the ruine elements l() and ll and thelateral stillness l r .s raped link T and the double o? the bromf. r,-

1 .l arm .ever elements 5 8 and Q--which closely einhraf-e and supporthotl.- the intermeil i snrmgf l-sron lj.' re

Y iceinent ot the r.i-li all and axle par ihe braclet ll by an;vsuitable lient suspension elements-such. im cx; mple; as eithersingle-actirgi` or doul'ilc-actinfg helical coil snincjs interposedhet-weon the ends of the relatively movable parts l0 and ll-but in orderto attain a high degree oli sensitiyeness; as well as a Emi wide range,in the cushioning and shock absorbing; action, l prefer to employ, forthis purpose, some torni of luidpressure cell, the elastic resistance otwhich, can be readily varied as required by altering-j the quantity otfluid `in the pressure chamber. V ,lh-e 'form oficell construction whichis shown in Figs. 2 and 3 adapted for use in `the organization ol 'Fig'.comprises a` l'flexible corrugated metal tube or bellows 1l which issoldered or otherwise hermetically sealed, at its lower end to a rigid had 13, and which .is similarly attached at its upper eX- treniity., toan annular ring or cap 16 on the top Lof a thin sleeve 17 that.surrounds the tube 1.1L and extends downwardly to a point near the lowerend thereof, where it terminates in a lla-nge collar'lS. This collarcai'- ries second corrugated metall bellows 19, which is soldered. atVits upper end, to a coneshaped head 2O that is sealed. in turn, to aflanged cap bolt 21. by iiuiansot' a sott metal pacliinc' ring and nutQ2. rfhe eloncated head of the bolt is closelyenggagred by the uppercndof an inner tubular meinber 24, which is attached "to the ring` 1G; andthe lower extremity oe this member is hernietically closed by the cap Aheavy coil compression spring, Q6, is interposed between'this cap andthecentral boss Q7 which extends upwardly .trom the lower head 13.

The space enclosed between the head 13, the

metal bellows 14, the rinoV 16, the tubular 'member .2a and the cap kQ5constitutes one V'fluid pressure cell, which can be filled or inptied`through either lthe screw closed opening` 28 or lthe valve controlledpassage way 29 in the lower head. The space between lthe substantiallyintegral parts 20- 21, the metal bellows 19` the collar 18, the sleeve17 and the ring;` 1G, 'forms a. second pressure cell to which access isobtained through either Athe pluslr closed vent 30 or the valve closedduct 31 in the upper head and bolt members 2O 21. Each of these cellsmay be partially lilled with oil, or other suitable liquid; and each ischarged with compressed air or other amiropriate gas until the expansionpressure on the vheads 123 and QO-which is due in. part to the fluidpressure in the cells and iii part -to the initial compression that maybe imposed on the spring` QG-is sufficient to balance the static loadstress to which the tensioned spring` elements are subjected when theyinterposed between the eppoi-tine' ends ot lever actuatd plunger 10 andthe body connected casing;` 11. and the assembled members are supportedin the median normal load position of Figs. 1 and 2. lt will be notedthat the cell ends,1G` 18 and 25, are held in fixed relationship to eachother b v the longitudinally rigid connectors 17 and 24; aud under theconditions just specific(L the torce exerted on the upper movable endwall ol the tinner cell-which is equal .to the Huid pressure therein`plus tlhe lnormal or initial tension imposedL on the compressionspring' Vthis latter torce 'being due to the gaseous pressureinthe-'outer chamber, reinforced to some slight lextent `by the actionot` liiid which may vleal; from tlie said chan'lber, past the closelyengaged partsill an( il-il, into the space'above the cap 25 The twoufncentric cell elements thereforeact ou the opposing; heads 153-27 and20%21, as though the itl cells 'were arranged end to. end, or in serieswith each other; and any relative approach movement of the said heads isequitably divided .between the two cells ,and elastically resistedY bythe cooperative and concurrent and substantially equal compression ofboth -ot' them. The expansive and con tractive motion oit each ot thezorrur'ated metal walls 14 and 19 is thus reduced vto one-half of whatit would be it" a single flexible bellows was used to ilirovide tor Ithesame change in the volumetric cap;` ity ot the `fluid retainer.

The opposing heads 13 and-:'20 of `the fluid pressure spring may bedirectly attached,

the one vto the axle supported lover and 9 the otherto the bodysupported casing 11; and in such case the relative movements ot the saidheads are `the same, 4in direction and amount, as the accompanyingmovements oitl the body horn 2 andthe :idljacent end of vthe rmainspringl 1. But I pret'er to construct `and arrange the relativelymovable parts ot' my suspension sys 'tem in such manner that the heads`13, and

2() Vare drawn toward each other-with a. resultant 'compression of Athesupplemental spring elements-by a movement ot' the body and axle partskin either direction from the noi-'mal 'load position. This .one waymove- `ment of ythe secondary spring element-tor aftwo way movement ofthesyningsuspended chassis parts-further reducesthe maxisistance ofthese cells in restraining' both Ythe compression and the rebound oreXpan- -u'iuin distortion oft' the flexible walls of the `seriesvconnected pressure cells, and aise `nir-lies it .possible to utilizethe elastic ref with the acl-jacent flanged extremity 35 of `the casing`sleeve Btl-(which is rigidly se- .l

cured in the bracketll by means ot the `screws 537-3? and the nuts 23S-38 on the cross-tie-rod 39)-and thus limit the downward movement ot saidplunger, and its head, with respect to the body supported bracket ll.The lower head 13 ot the `fluid spring' rests on the upper surface ot'the plunger head l; and the upper head E20 ot this spring` is secured toa cap 23, by means ot a nut 23 on the upper end ot the bolt 2l. rlfhecap 2.5 is operatively connected to the bracket ll by a short tube l0which is provided with a shouldered end that is alapted to engage thereversely turned flange oit the casing sleeve- 36. and thus limit theupward movement ot the parts 'Q3-2O with respect to the body members.The flange is cnt away, at two diametrically opposite points n itsperiphery, to receive tb lshaped heads el ot a pair ot connecting straps42 49, that extend downwardly through suitable guide openings, fll., inthe sides ot the bracket l1,

id are perforated at their lower etren'iiw ties to receive the ends oithe pivot connections 32-32, which project out through slots el in thesides of the lower head '.lhe operation of this construction is aslollows: lilhen the parts are moved from the full line positions N-n ofFins. l and 2 toward the positions shown in Fig. l (or the dotted linepositions C-C-c ol Fins. l and 2)-as by the action ot a compressiveshoelrhthe auxiliary head 33 engages with the head l5 and li'ts thelatter toward the cap Q3 which is now held in tired position withrespect to the bracket ll by the engagement ot the shoulder on the tube.4.0 with the flanged head S5 ot' the casing sleeve 36. This movementalso lil'ts the connecting` straps -l-Q; but this action merely carriesthe n"shapcd heads l-.l of the straps up out ot engagement with theshouldered end ot' the tube l() and has no functional ell'ect. lint whenthe body and axle parts separate or expand beyond normal load positionand move toward the lower dotted line positions llwll-r ot Figs. l and2-the 'l'miape l heads ll engage with the inwardly turned shoulder onthe cap tube 10, and th downward movement ot the lever i and pivot bolt32 then draws the said tube and its attached head .J3 toward the lowerhead 15x-the latter being;` now nrevented from 'following tin movementor the lever and the auxiliary guide head 33 by the engragen'ient ot thellanfe 3l on the plunger lube Vl0 with the flange on the casing sleeve3G. ln order to eliminate any lost motion between the successivelyengaged parts S23-l5 and l0 ill, suitable prov sion .is made for theidjustn'icnt of the ends ot the pivot bolt with respect to theconnecting straps l2. ln the torni of construction shown this adjustmentcan be ellected by rotating the l'iushingor sleeve Ll-which has apivotal bearing' in the men'ibers 5 and llhand clamping it in thedesired position between the ends of the said straps by nieans ot' thenuts on the ends oit the said bolt (in the saine manner in which theeccentric collar on the bolt 9 is clamped between the ears S-Q, Fig.l2).

rlhe relative approach ot the two heads l5 and 23-whether produced by acompressive n'iovenient or by a rebound movement the suspension systemas a wholev-is accompanied by a corresponding approach ot the springheads 13 and 20, and this motion is elastically restrained by theprogressively increased compression o' the two series connected pressurecells (or by any other torni olf supplemental cushioning; spring' thatniay be interposed between the said heads) until the cell ends 1G and 18have been brought into engagement, respectively, with the heads 2O andl5; and the various partsv are pret'erably so proportioned that thislimit o't supplen'icntal springT coinpression is reached concurrentlywith the engagement o1" the pivot bushing 32', either with the lowerextremity ot the easing sleeve Sti shown in llig. el), or with the lowerends ot' the slots ll as shown in the lower dotted lines ll-r ot' Fig.2). A continued approach movement ot the body and axle parts (alter thelirst mentioned engagreinent) is pern'iitted, but is very el'liectivelyresisted a` d rapidly checked, by a further positive bending, andstraightening ont, of the already strongly flexed main leatl spring` l.l3nt in the case otl rebound or expansion movements the primarysuspension member is locked against any reflex or negative bending (bythe interengagrcnient oll the relatively rigid lever-stop elements andconnections, 5-G-7Slfg and when the sejaration olf the verticallyoscillatingv chassis parts is sullicient to bring;` the leverconnections 23e-3Q into contact with the bottoni ol the slots lll, anyfurther cx* pansion ot the system is very quiclrl f arrested by theresistance ot' the relatively stift lever member 5 to edgewise fiexure.

My i veniion may, in some cases also include means for damping;- orslowing the recoil or return ot' the spring elements 'trom theirabnormall'i stressed and flexed conflition to the position oit staticeoluililu'ium, ln the exeinplilication shown in Figs. f2 and lthisdamping` ell ct secured by providing the collar l? with a flexiblepacking or wiper ringe', -Ll-vu which engages with the inner surluplunger tube l0.y and which is of such lorm as will permitthe air belowthey collar to escape freely to the space above ,it-wehen the parts moretoward the position ot Fig. l-but will prevent any reverse Vflor-.f it'vlluid when the parts return to normal load position. The recoil ot thelll() port on the plunger compressed elements is therefore retarded bythe creation of a partial vacuum on the under side of the collars orrings 18 and 16; and this retarding effect is progressively augmented asthe recoil movement proceeds, until the return of the parts 'to thenormal load position of Fig. 2 permits air to enter the space below therings lS- through a row of small vents 46 (which also serve to indicatethe correct relative location of the mutually reciprocating plunger andcell members when theyk are in the said normal load position). itsimilar and cooperative damping eifect on recoil movements may beobtained by providing` the bearing between the tubular member M and thehead of the bolt 2l with a wiper ring 47, which is held in closepressure engagement with the surface of the tubular n ember by a springexpander ring d8. lilheu the inner cell is compressed to maxiinuinamount the cap 25 is brought into close proximity to the end ofthemember 2l, and substantially all of the fluid which may have leaked intothis space, from the outer coll chamber, is driven bacli into thatchum-- ber, past the outwardly yielding" wiper ring di'. When the recoilmovement occurs the pressure in the expanding space above the cap 25 isgreatly reduced and the return ofV the parts to normal load position iscorrespondingly retarded. Vthe recurrent reciprocation of the engagedparts 2l and :2li also serves to prevent kany accumulation of Afluidpressure on the upper face of the cap 25, and correspondingly increasesthe supportingeffect of the cooperative spring forces that are acting onthe movable end walls 16 25 of the inner cell.

lihe air which is driven upwardly intor the annular chamber above thewiper ring di, and is further compressed in that chainber by approachmovements of the plunger tube l() and the cap 23, will be, in part,expelled through the vent openings e6 into the bearingspace between theplunger l() and the casino' sleeve 36 (see Fig. l); and will serve toblow dust and grit out of the lower end of this bearing. f in the courseof long continued operation either the tube l0 or the sleeve i336becomes unduly worn, one or both of these members can be very easilyremoved and a new part or parts substituted therefor.

rThe supplemental spring elements of the above described combination canalso be easily detached as a unit from the of the organization bysupporting the weight of thevbody member i), on a suitable jack and thenremoving the lock nut 23 and the cap 23; after which the entire springassembly may be lifted away from its sup- 1 head 1:`i and replaced, ifdesired. by another duplicate ln order that these operations may becarried on with fully charged and pretensioned cells l provide suitablestop elements which limit the expansion of the spring parts by theinternal pressures. In the illustrative forni of construction now underconsideration the limit stop for 'the inner cell consists of a cap boite9 which is screwed into the end of the lower head extension 27 andwhich is engaged by the flanged end of a tubular extension 50 on the cap25. The erfoansion of the outer cell is correspondi V,ly limited by acap bolt 51 that is screwed into tbe cap andis engaged by a flangebushing 52 the lower end of the bolt 2l. ln the initial assembly of thespring elements the bolt i9 is so adjusted that the niirunn allowableseparation between the heads L13 and 20 is slightly greater than thenormal distance between the plunger and casing heacs l5 and and thespring cells are charged with fluid until the desiredV load carryingcapacity is attained; after which. the valves in the passages 29 and 3lmay be p 'wuianently sealed. By preparing and keeping in stock a numberof these charged f varying elastic resistance it becomes pcc to easilyreplace or renew .leaky or defective air spring elements of differentsuspension organizations; or to quiclily change t ee elements, whendesired, to most eifcctively deal with varied conditions of load and ofroad surface. rlie entire ab sence of any sliding joints through whichthe confined fluid may leal; to the exterior of the spring eliminatesany necessity for recharging or renewal, or any other inspec tionservice unless one of the flexible walls of the air cell becomesruptured-or one of the permanent seals at the ends of the said cell isimpairedby the effects of long continued vibration and oscillation. Butthe possibility of such injury is reduced to a minimum by the use of themultiple-seriesconnected bellows structure-which greatly increase theeffective length of the longitudinally Flexible side walls of the celland thus greatly diminishes the maximum contractive and expansivemovements of the individi'ial folds those walls-and by the empi'oymentof double acting limit stop connections between the main andsupplemental air spring members of the combination, which prevents anyexpansion of the air cell elenients beyond their initial normal loa dform and volume, and reduces the maX- imuin compression thereof tosubstantially less than one-half of the concurrent relative oscillationsof the spring supported body and aide menibers. The possiblelife of acorrugated metal bellows-when subjected to repeated contractive andexpansive movements-.-increases very rapidly when the bending ordistortion of the individual cor-I rugations thereof is decreased; andbot-h of the last specified features of my present inlll vention (whichmutually contribute to the diminution and minimization of the saiddistortion) are therefore of particular importance in conjunction with`the use of permanently sealed fluid spring elements such as have beenheretofore described.

rlhe construction depicted in Figs. 5, 6, 7 and 8 presents the sainegeneral features of structure and of operation as are characteristie ofthe previously illustrated form of my invention; but this secondexempliiication of my improvements differs from the first in variousdetails of construction. In the arrangement shown in Fig. 5 the leverelement 5il is rotatably mounted, near its inner end, on the axle bloei;6, and is coupled, at its outer extremity, to the end of the main springl by means of the hooded shackle link 7a. This lever is not directlyconnected to the plunger element l0a of the supplemental spring member.but is operatively conjoined therewith by means of the auxiliarytwin-arm linl bar 53, which is coupled, at its opposite ends, to thelower end of the said plunger (by the pintle bolt 32u) and to anupwardly projecting` boss on the median portion of the lever lO (bymeans of the pintle bolt 54), and which is also coupled near its center,to the body horn 2 of the vehicle, by means of the one way adjustablestrap connection 49a. The inner end of the lever 5 projects beyond theaxle and axle block 6a, and is provided at its extremity with anadjustable screw 9a that is adapted to be engaged by a coned recess inthe top of the block 55, when the parts are in the ful line normal loadposition ll, as shown in Figs. 5 and 7.

rl`he operation of this portion of the sus pension system is as follows:When the springr suspended parts are subjected to kinetic compressionstresses the upper edge of the lever 5 engages with a cross web betweenthe arms of the link 53-er with the adjacent lower end of the flexiblestrap connection 42u; and the relative approach of the body andaxle-main-spring members raises the ii'iterengaged lever-link elementsnh, as a unit, and correspondingly lifts the plunger l0 against whateversimplemental spring resistance may be provided for the restraint of suchmovement. rThis compressive movement is accompanied by the usualincreased lexure of the main spring l; and the resultant flattening andstraightening out of the primary suspension member resi'ilts in a slightclockwise rotation of the connected lever-link elements 5--53 on themain pivotal support 61 therefor, and thereby carries the stop screw 9out of engagement with the recess in the axle block 55 (as shown indotted lines in F `When the system is expanded beyond normal. loadposition the screw 9a engages with its axle supportand thereby preventsthe main spring from reflexing or recoiling beyond its normally flexedform. rPhe interloc'zed leaf spring', lever and axle elements, l-L- fao--7-9=1`55, then move downward, or away from the body, as a rigid unit;but the pull of the strap connection d2 on the linhV bar 53, roels thelatter in a counter-clockwise direction on itsI downwardly moving leversupport 54; and thus moves the plunger l0 of the supplemental springincnibor in the saine direction as it is moved by the con'ipression ofthe system. The relative positions then assumed by the lever 5, thelinl; and the secondary spring supports, are shown in Fig. 6; and acomparison of this ligure with the dotted line indications of liig. 5(which outline the parts in the position of extreme compression) makesit apparent that thc supplemental spring elements of this combinationwill always be moved and flexed in the one direction-i e., upward withrespect to the body supported member 1lb-whenever the other parts of thesuspension system are displaced in either direction from the normal`load position, if. of static equilibrium. lt will also be apparent thatthe conjoined lever and linlr elements .5L-53 act as a longitudinallyrigid radius rod that will serve to maintain substantially unchangeduistance between the axle supported bracket (5 and the body supportedplunger and casing members l0- lll; and that the mul iiple pointoverlapped engagementbetween the sides of the double arm U shaped linkbar 53 and the adjacent edges and faces of the parts l, 5 and 7 lgivesto this radius arm connection a high degree of transverse stability andrigicrty that will effectively prevent any side sway, or any relativelateral displacement, of the vertically oscillating parts.

The plunger support il may be constructed, and connected to the bodyhorn 2, in any suitable manner; and the upward movement of the plunger10a, in the said support, may be elastically resisted by any appropriatetype of single acting` spring` construction. fis illustrated in F 7 and'8 the sides and cap of the member ll are east in one integral piece,which is bored and lapped to form a goed bearing for the upper end ofthe straight plunger tube l0, and which is preferably recessed andthreaded, at its lower end, to receive a packing ring and a renewablecasing sleeve 3G that supports and guides the adjacent portion of thesaid plunger. rilhis support is provided at one side with a boss toreceive the end of the cross tie rod 39 and is recessed and surfaced onits opposite side to receive an exten sion bracket 5G that is securedthereto by the bolts 57, and is clamped to the body n La horn 2 by meansof the bolts l2l The lower end of the plunger tube l()vll is bric/.ed orotherwise permanently attached o he lll) cap 15L that carries thepint-le bolt 3%; and the upper side of this cap is faced oli to receivethe head 13 ol a fluid pressure supplemental spring element that isdetachably secured to the said cap by means oli the stud bolts 58. rllheopposite head 21 of the supplemental spring is supported by the top capoli the member 11 and is clamped thereto by the nut 23% The heads 13 and21 are elastically united by the three longitudinally flexible metalbellows 1l, 141:1 and 19 that are connected in series with each other bythe longitudinally rigid equalizing` sleeves. 1T and 1.". rhe upper endsot these sleeves are attached to radially engaged rings or collars, 16and 16" which are in respective sliding: contact 'ith the exterior ofthe head 21 and with the internal bore ot the support 11; and the lowerextremities thereof terminate in perforated annular caps 18 and 18 whichsurround the central boss 27 olf the lower head 13, and are limited intheir upward movement thereon by the shoulders 59 and (il). The boss 27is also provided with a hollow cap extension 49 which adapted to engagewith the head of an adjustable bolt 51) that is screwed into the upperhead 2TH; and which thus serves to limit the relative separation orexpansion ot the supplemental springi heads 13 and 2l r-i heavycompression spring 2G is interposed between the adjacent ends ol* themembers 21 and 2T and serves to assist in resisting the approach otthese parts.

rlhe space enclosed by the lower head 13, the outer 'bellows 19, thetransmission sleeve 171, the intermediate bellows 111, the transmissionsleeve 17, the inner bellows 111 and the upper head 21, constitutes asingle fluid container or pressure cell, which can he charged with thedesired quantities ot liquid and gjas, either through the opening lettby removingv one of the stud bolts 58 from the lower head, or throughthe valve controlled pasage Way 31 in the upper head. Vv hen so chargedthe expansive pressures acting on the upper ends or heads 16m and 16 ofthe two annular compartments, 19-17 and lm-m17, are successivelytransmitted through the equalizing` sleeves 17 and 17 -to the perioratedlorver end plates 18M and 18-(vvhich limit the expansive movement of the'flexible Walls 19 and 142 by the cooperative action of the stopelements GO-59 and 49h-5W)- and the supporting effect ol these pressuresis thus communicated, and added to the expansive force exerted directlyon the upper central head 21 by the l'luid which lills the centralcompartment (Within the inner corrugrated Wall 1Ll) and by the initiallystressed compression spring 26. Vhen this resilient assembly isinterposed between the opposing,` ends ol the members 10 and 11'reduction in pressure, or a part and is compressed, by the telescopicapproach movement of vthe said members, the coil spring 26 shortened,and increasingly lleXed, by the full amount oi such movement; but thechange lin the length each one o't the series connected corrugatedWalls, 141e, 1/l and 19, is only one-third o the 'total compression. lnorder to positivelyrcontrol and limit the balanced fluid pressure actionon the three longitudinally flexible members last mentioned (and preventany one ot them from assuming` more than its proper share ot an extremeclosing movement), the rings 16, 16 and the end plates 1S, 1S,

are so shaped and positionedf-with referif" ence respectively to the cap`ot the casing support 11 and the lovfer head 1l-that, at tno point olimaximum compression, the rings 16, 16m will have been, concurrently orsuccessively, engaged with the casing cap7 and the said plates 18, 1821will have been correspondingly brought into contact With each other andwith. the central flange oli the said head 13;--as shown in thesectioned portions ot Fig. S.

lt will also be noted that the pertorations in the members 18, 18, areso arranged as to leave a lree communication between the successiveannular compartments of the i'luid containing;` chamber even when theparts are in the contacting positions of maximum compression lastdescribed; and the equaliaingij i'loiv oi liquid-(Which lills the lowerportions ol these compartirlo-nts, or may in some cases completely lillthe outer tivo compartmentsbwpast these relatively movable end plateswill, therefore, never be interrupted But these equalizing openings may,if desired, be made of such restricted sine as to oller an appreciableresistance to the fioiv of liquid through the moving parts; and theoscillations ot1 the fluid pressure spring may tluis be hydraulicallydamped. The return or recoil oli the compressed resilient elements-from'the abnormally 'flexed condition illustrated in Fig. 8 to the positionot normal load, or sta-tic equilibrium shown in Figs. 5 and T-may alsobe retarded to an additional degree by providing` the top of the member'11 with an outwardly opening valve l5 Which Will permit the ai-r to passout of Vthe space above the rings 1G, 161 on the compression stroke; butwhich Will prevent the reentry of air to this space on the expansionstroke. The return or recoil movement ol the contracted parts (from aposition ol compression such as shown in S) will therefore produce a ialvacuum, in the expanding space below the csp oi the support 11, andthepneumatic restraint thus imposed on the expansion movement ivillprogressively increase as the movement continues, until the restorationof the parts to normal load osition Fie, 7 uncovers lllfa lll) ldd

stt)

the end et a passage 4G that permits air to once more pass from a pointOutside the valve @toa to the said space. rlhe pneumatic dampingl actionlast described may be further suj'iplenicuted, in some cases, byproriding). the lower end ot the hollow cup ll with a ventthat is closedby an outwardlv opening` flap valve 47a. In such cases the movement etthe cap bolt 50FL toward the head 27a will force the fluid in the hollowcap past the valve 47, but on the reverse or expansion movement the saidvalve closes and a partial vacuum suction pressure is exerted on therelatively separatingr parts, 5th-21a and QTL-49a.

rlhe opening` above the valve 45 may comn'uinicate directly with theexternal atmosphere; but l preter to utilize the air er:- pelled throughthis valve, on each compression stroke, to blow out the dust troni thelower end et the plunger bearing. ln order to accomplish this object Iprovide a lateral duct 6l which leads trom the closed pocket containingthe valve lo to the top ot a vertical passage way (32 in the side wallot' the member lla. The lower end ot the passage G2 is in registery witha grooved opening G3 between the engaged taccs ot this n'ieniber and itsbracket support and this opening communicates at its bottom with the topot the annular recess into which the casing` sleeve 36a is threaded.Each upward movement ot' the plunger torces a certain amount et airthrough the passage ways (il (SQ- (38 into the space above the sleeveilo, and thence downwardly and outwardly past the dust packing ring andthe guide bearingl surfaces at the bottom of the plunger barrel. lnorder to replace the .fluid thus expelled on each compression stroke lprovide an inwardly opening valve (Sl at the top` ot the passage way 62(or at any other convenient point) which will admit a correspondingquantity of atmosplier-ic air on each subsequent expansion strolre.

The. operating parts et the supplemental spring construction lastdescribed can be easily disassembled by removing the linl; connection523 and the lock nut 2311; alter which the plunger 10a, and the spring,`cell supported therein, can be withdrawn trom its guide support 11, andthe cell element detached therelroni, as a unit, by removin` the nuts onthe stud bolts 515, Repairs and replacements can be malle 'very quicklyand easily by keepingl in stoel: a number et supplemental spring unitsthat have been inflated to various load carrying capacities forvaryinfiA conditions ot service; and the supplemental lever-stopsuspension mechanism may also be readily adjustetl, to maintain theoperating` parts in the proper position for diner-ent static loads, byvarying the length ot the tlexible strap connections Qa-(as by the use01"' eccentric cross bolt and collar supports at the ends thereot)-andby altering the angular relationship ot the lever and link arms :TL-53,either by usingr an eccentric bolt and collar at the pintle connection5a (such as is shown either in Fig. 2 or Fig. l2), or by using anadjustable screw stop (i5. lt the plunger tube bearingl becomes undulyloose al'tcr very extended service the casing sleeve 3G- and itnecessary the straight plunger tube ith-can be replaced at very smallexpense.

les. t), l and ll depict a third embodiment ot my invention. ln thisexemplili lation ot my improved suspension system the lever element b ispivotally attached, at its outer extremity, to the lower head l5 ot theelastically supported plunger tube b; and is also coupled to theadjacent eye end olI the main spring' l by means ot the U shaped shacklelink 7b. This lever is roclrably mounted, near its center, on the axlebraclret 6"; and is provided at its inner end with an adjustable stop 9that is normally so set as to maire contact engagement with the adjacentportion et' the main spring` l when the parts ot the suspension systemare in the position ot static equilibrium. Under such conditions otadjustment the lever-stopsuspension elements 5b-6b7b and 9b act in thesame manner vas the correspondingly designated parts of the first desafibed organization, in permitting` an unrestrained increased ilexure ofthe primary springl support when the system is subjected to kineticcompression stresses, and in preventing any recoil or relexing,` of thiselastic member beyond its normal load form when the tem rebounds orexpands from the position of static equilibrium. ln this case theplunger tube l0b is always connected to the end oit the lever 5b, andtherefore nieves with the said lever and the main spring, both oncompression and on rebound n'iovements. rlhe supplemental or secondaryspring member, which serves to elastically support and control thereciprocating plunger, is therefore, preferably, of such character aswill enable it to resist displacements ot this element in eitherdirection lrom normal load position.

Figs. l0 and ll illustrate one form. of acounteracting-secondary-sprlnir construction which is suitable tor usein conjunction with the mounting shown in Fig. 9. ln this loi-m otstructure. th lower head 13" of the conibination is slidably mounted inthe j'ilunfcr tube 101 and normally rests on the lower head l5 thereot.rlhe upper head 2l" is clamped against the cap ot the plunger `cuidesupport lll by means ol the lock nut 23"; and is provided with a long'hollow sleeve D which terminates in an inwardly turned collar 511 thatis adapted to engage with the adjacent flanged end 49", ot the lll()centraLextensi on i 27 l: on .the lower head `13b, and V#thereby`limittheseparation vor -expansionof the two heads.. The, extension27l5is provided witlramhollow piston66 that .tits closely finthe sboreotthesleeve .56h and is closedatits upper end adished-.cap 67. The .member27h is `also bored-to receive a rod68 that issecuredat its lower end, tothe plungenhead ,1.3?-by means of. the threaded pivotbolt ycap 15candthe cap bolts 69-and is provided'at its upper end with a head 7 0that.,slides.V in the a hollow piston 66. A strong compression spring 7lis conlinedat considerable initialtension between. the head70..and-the..tla11ged end 49" otthemember 2.7ll .The rod .68. :hasacentralpassage way 72,1.which communicates,-` at .its lower end, with4a' transverse .openingj' in the iblock l5?, and iwhich cis. provided.wi-th. a series .of lateral- :ports .747. of lcontinually increasingsize, that` are-preferably.. spaced at substan-` tiallyvequaldistancesalonggthe .line o't`.bear,. ingnengagement. between the saidrod andtliecextension. member 27h` vThe-heads.13b and ,Qllare connected to theopposite endsiof a fluid pressure cel1,.which isY .similar in..construction .to Ythe one. `shown inr.Figs. Y.7 and r .8,- -but whichicomprises.; .f in this case tour. .concentric :longitudinally Hexiblemetal-bellows,.142.142219th, and '19", that-.are operatively connectedto act in series by means. of the intervening :longitudinally lrigidsleeves.17h,1.171?b and 17%' The upper ends. @tithe-.vsuccessi-veypairs of flexible tube and rigid .sleeve t elements. 17 1 -Mb, 17m)-l9ll, .and .17'7-191; are .secu-red i together .by theaannular:rings16h, 16Vb an'dlGC-'which are in .sli-dingengragementl with eachother andwith the. upper :head .21 an dY the' .outerl support 11b.. Themlower'ends of Ithe `suc-V cessive'pairs of concer-nariov elements, 14N-17h,14N-171221 .andx 19bb^17, are correspondinglypconnected .byV therannular iperto-rated endplates 18"), .118ml and 1Sc,:all2otwhich slideon the centralfstem.271%, and are-respectivelyliinited intheir..upward'motion thereo1i-,l;iytliesuccessi-ve#shoulders 591%; 59W`and Y The `spaceenclosedbetween the lower head members V 1b-'27"-, thesuccessive pairs' otflexiblef and `rigjicl-elements 19"-172 19km- 171,Mtl-17b and "ML-50h, the-upper head 2lb; andthe hollow piston-66-67.constitutesl a tive compartment chamber, which can be filled ordiscl-iarged either throug'lrthe openH ingf'that is normally/closed andsealed by the cap screw 28", or throughfthe valve con*ytrolled,passageway7 31h, inthe upper head. The four outer compartmentsare always in communicationwith each other tl'irough.

the-.perforations inethe end plates 18h; 18" and 18., which are. so4arranged as to. remain open even` when these. plates .have been,

brought into. surface` contactwith each other by the extreme'compression'ot' Vthe' fluid.

5 SP1-ins elements; and the-inner Cempeltmenb periphery ofthe said head;and when the p inner end of this duct is closedbyth relative upwardymovementof the .ring 1r6bfon the compressi on movementthe air in thatspace can stillfescape \.-(but`cannot enter) pastthe'tlexible wiperringkvalve lbfonthe outer bearingperiphery ofthe collar 116C; The.operation of theabove described sup; plemental yspring `structureI islas follows': VVfhen the axle-main `spring .,inembers, i and the Vbodymembers :are forced toward each other-trom the normal load positiolrNL,ofy Figs, .9 and 10 toward .the dotted line positions C of Fig. 9-theplungermembers '15--15l--10b are moved Vupward with re- Spect to thesupport 11;` and vthe volumetric capacity-ofthe fluid chargedvsupplQIIlQ-Iltal springchamber isreduced bythe correspondingapproach ofthe i head vmembers- 13%27'-6667and @b-50". The mechanically .controlledmovement of `the two parts 501%` and 66-.67 .immediately closes theequa-A lizingports 7 5; and the increasedcompress ion of the trappedAgasin theginner .compartment .26h Vis thereafterindependent of; and.acts in .parallel.with7 the concurrent compression of the-gaseousportionotfthe fluid .in the continuously-A connectedoutercompartmentsthatare simultaneously, or semi-successively,\ reduced involume by the conjoint pressure balancedmovementsofthe Hexiblysunitedcell endsI 2li-T18", l-3" 18W,k 16.9""-180` and 16C- 13h By properlyproportioningthe clearance space betweenthe dished -cap .67andtherecessed end .ofi the head 21M-as compared with the. remainder otthe liras filled spacein-the fluidy containing; chamberfftheincreasedcarrying capacity ,that .resultstrom the maximum compression Aof the gas.or air in the coniartment 26"mav: be made toe ual or even:

exceedp thewparallel effect that is lobtained by the 'separate.compression of the gaseous fluid in. theouter compartments.`Thelcompressed. elastic.. fluid :that .i s trapped. in i thefspaceabove the. capf67l-fby the closureot the. equalizingportsl-#therefore performs the 4'function otltheV initialli7 tensioned coilsprin 2G andV 426T (used in the i-r'st-i` two described, exemplifcations,et my inventionlf; Vand may, .liltethose coiled elements',. be .uti-`lzed to carry any:desirediproportionofthe.

increased i'stress that.. is.y imposed on the 1 secondaryelasticzsupportrbythe.kinetic com-.

pression 4.of the. suspension .Q system. Y.. This weilarweeenf.@fieberrisldrleeesrfsetuff CSI ated pneumatic spring 26h, thereforeserves to diminish the pressure strains to which the flexible wallelements (Ll-b to 19h) would otherwise be subjected. The maximum strainsthat can be imposed on these ilexible metal falls are also limited by soshaping' and so spacingthe end rings 16", 16hb and 16C-with reference tothe cap ot the casing 1l" (or so positioning; the corresponding andcoactuated end plates 18h. 18m or 18 with respect to the lower bead 13b)that no one of the corrugated tubes, lill, 14"". 19" or 19", can becompressively shortened to a greater maximum degree than one-fourth otthe extreme closing' moif'ement ot the parts 10-l3b toward 11M-2lb; andany est ssive distortion that might otherwise be imposed on any one wallt by reason ot the greater flexibility or longitudinal elasticity ot thecorrugated metal folds thereof) is thus prevented.

The approach of the end rings 1G", 16m and 16C toward the cap oi thesupport 11b expels the air from the space between these parts-throughthe downwardly openingwiper ring` valve 45--and when the compressionmovement is arrested, the recoll or return ot' the abnormallyT lexedspring eletnents is pneumatically damped or retarded by the formation ota partial vacuum, or oi a procfrressively reduced pressure. in the topof the guide member. l/lilhen the normal load position is reached thecollar 51" engages with the flange 4-9) and thus positively arrests therecoil or expansion movement ot the supplemental spring; but thecontinued rebound or expansion of the suspension system as a wholecarries the lever actuated j ilung'cr parts, l0h-l5c-l5b68 and downward,or away trom the expanded, and vnow inter-locked. casing` supportedmembers 2lb-50l-27"-l3b; thus imposingF an increased compression on theinitially tensioned coil spring' 7l, and also creating' a partialvacuum, or a progressively reduced pressure, in the expanding spacebetween the heads i3" and l5". These coiicurrent actions impose acontinually increased restraint on the separation ot the body and thenow interlocked main sprint;- liwer-axle elements (l---5-6l-7b-9b ete),that effectively supplements the action ot gravity in resisting andchecking the rebound or tossing of the tonneau as a sequence ol anabnormal compressive movement of the suspension springs. The reboundrestraint eXerted by the spring 71 is rapidly increased by theprogressive closing of its coils; and when these are brought intocontact with each other the turtherievpansion movement of the members10"-ll" etc. is substantially arrested. But the pneumat-ic component ofthe rebound restraint may be maintained constant-or even diminished asthe rebound movement continues-by the progressive uncovering ot' theports 74: as the rod 68 is drawn out ot thc head 13"-27", and air isadmitted in restricted amount to the expandingv chamber below the saidhead. This restricted intlow ot air into the expansion space results ina correspon ding,l positive increase in pressure above normalatmospheric value) when tbe expanded parts are restored to normal loadposition; and the recoil of the supernormally flexed rebound restraint"spring 7l is thereby damped and cushioned on the return movement.

The air that is compressed in the bottom of the pl ui'iger chamber willgradually leak past the ,(rooved sliding; joint between the head 13" andthe bore of the plunger tube l0" into the space between the said tubeand the outer flexible wall 19h, and will be mixed with the air which isforced into this same space past the wiper ring valve 45" on thereciprocating; collar 16. On each compression stroke a part of the airthat is thus a cumulated in this outer chamber is forced past theslightly enlarged, and longitudinally grooved. head ot the plunger tubel0 into the annular clearance space 631 below that head.' and on thenext expansion stroke some ot this air is, in turn, blown out ot thelower bearine` between the plunger tube and the renewable casinp; sleeve361. and thus assists in keeping that bearing free ot dust and grit.llllhen the guide bearing` surfaces have bei-omc unduly loose. aflterlone` continued service, the bushing 36, and if necessary the plungertube 10b, can be renewed at very small expense. And it' the walls or anyof the sealed end joints ot the herinetrically closed fluid pressurechamber should be accidentally injured or ruptured. the springr cell canalso be removed as a unit (and another fully assembled and charged cellquickly substituted therefor)- b v detachine the lever 5" troni itspivotal connections with the axle bracket G" and the j'ilunc'cr cap 15C,reimn'inig` the lock nut 23" and the bushing' 35". and withdrawiner theplunger. with its attached parte troni the support llf: atter which thespring* cell assembly is readily separated 'from the plunger members bytaking out the can bolts tif) and nnscrewing` the cap l5" 'troni the endot the rod G8.

The various iol'lns of volumrtriralljv olaz-ftic containers which are ihistrated in Figs. 2, 3 and l, 7 and S. and Figs. lil and il, respeltively. all present the saine basic features oi" structure: viz,relatively riiii-"l end walls or heads which are united bv a pluralityot lonnit-iidinall)v flexible or elasti-.l side walls. that are nested.or concentrieally arranged. one within the other. and are hermeticallyconnected in sc s bv terveningg longitudnallv riejid eres. u The fluidcontainer' is thus divided into a number Elfi ltlfi llll of compartmentswhich may be entirely cessity for constant flooding, and continuousseparated from each other (as in the first described construction), ormay be in continuous communication at all times (as in the secondexemplary construction), or may be in part in continuous communicationand in part intermittently isolated from one another (as in the case of'the live compartment construction last described). The diameters of thesuccessive series-coupled flexible walls or corrugated tubes, and of thealternate 'rigid connecting sleeves may have any desired ratio; but arepreferably so chosen that the effective pressure supporting areas oi therelatively movable end connections between the said walls and sleevesare substantially, or approximately, equal to each other; and theseveral corrugated tube or bellows elements are preferably made o'lsubstantially the same length and of such form and material as to havesubstantially the same internal elastic resistance to detormation. Undersuch total external load stress on the opposing heads of the fluidcontainer will be evenly distributed between the various relativelyyielding, but elastically resistant, parts of the complete springassembly; and the compressive or expansive movements of the hermeticallysealed vessel will be provided for, and taken up, by the aggregate, orcombined flexures of the several series-connected flexible tubes whichact in substantially the same manner as they would if placed end to endto form one unbroken or continuous wall member. It is thus possible toprovid-e :tor a relatively large compressive movement of the springheads-which are operatively attached to, or actuated by, the body andaxle-main spring members of the vehiclewith a relatively small overalllength or height of the fluid pressure spring element, without imposing1 any sensible, or detrimental. bending or distortion on the individualfolds or corrugations of the flexible side walls thereof. I can thusobtain a very short and compact air spring cell which .is at all timeshermetically sealed, but which is capable ot large changes in volumetriccapacity and of very long continued vibratory action-under allctmditions ot pressure and temperature-without any undue fatigue, orcrystallization, or ultimate rupture of the elastic metal parts of thestructure.

The fluid pressure cells, which are used in the several hereinbeforedescribed exemplifications of my invention as exemplary forms ofsupplemental spring elements, may be filled with gas alone; or in partwith liquid and in part with gas; or, in some cases, with suitableliquid-vapor mixtures of low boiling point, such as sulphur dioxide,chlorine, eyanogen, ammonia, carbonio an hydride, etc. The hermeticsealing of the charged cell, and the elimination of all nelubrication,of internal pump and packing joints, ete. (such as are necessary inother existent forms of air spring' construction), makes it possible forme to make use of a wide variety of liquids, gases and vapors for thispurpose; and thereby avoid many ot the ditliculties that accompany theemployment of heavy oils, or other highly viscous liquids, inconjunction with compressed air or other oxidizing gases, in thecompression space. The permanently charged and sealed chamber of myimproved fluid pressure spring elements may, for example, be partiallyfilled with kerosene or gasolinefor the purpose of reducing the elasticfluid volume and increasing the compression ratio for a givenclosingmovement-and the remainder of the space charged, to the requisite loadsustaining pressure, with substan' tia-ily pure nitrogen or carbonioacid, or other inert or neutral gas. In the use of such forms ofmultiple connected compart ment cells as are illustrated, for example,in Figs. 7, 8, 10 or 1l, the filling may be conducted in such mannerthat each charged compartment contains a predetermined volume of trappedand compressed gas, or in such manner that certain compartments arecompletely iilled with liquid alone; and in either case the greatmobility of such fillers as have just been mentioned, permits of' therapid liow of fluid through the equalizing passages between thedifferent compartments (as the cell is compressed or expanded) withoutany sensible hydraulic damping of the movement, and without producing anemulsification or" foaming of thek liquid charge. The elimination of alltightly iitted high pressure sliding joints also diminishes thefrictional resistance to spring action, and completely avoids thesticking and freezing which result from the great increase in staticfriction that a"- companies and follows an extended period oiinactivity. The effect of all these contributing factors is tosubstantially aug-l ment the sensit-iveness and reliability ot operationof the elastic fluid suspension ele ments, and. to attain, to the lulldegree, the adjustability, the free movement', and the wide range ofaction, which is characteristic of the air spring as Compared with otherforms of solid metal springs of equivalent carrying capacity and ofequal resistance to kinetic displacements.

A further advantage of the hermetically sealed multiple wall type offlexible container, which has been illustrated herein as a part of mypresent invention, is that this form of fluid pressure spring supportmay be used in any position; i. e., with its axis of compression eithervertical (as shown in the preceding illustrations) or horizontal, orinelined at any desired angle to the body frame III.

of the vehicle. rl`.his maires it possible to utilize this improved typeof packless air spring` in. certain positions and in certain places-ason the rear side-leaf spring suspensions o'l" heavy truck trames-whereit is impossible to install the ordinary liquid seated term ol air cellin a vertical position because ot lack of head room or because ofinterference with the platform space. For these reasons this specialfeature et my improvements (viz, the hermetically closed or paclrless'tluid pressure spring support) has a wide range of application to agreat variety of elastic suspension organizations for different chassis'trame constructions. It is 'not however' necessary to employ anyparticular liorm ot' resilient support elements in order to obtain thefunc-tional control that is characteristic oi my improved lever-stopsuspension mechanism for connecting` and coactuating these elements; andin its broader aspects my invention is not, `for that reason, limited tothe use ot pneumatic or fluid pressure springs as the supplemental orsecondary members ot the suspension system.

It will now he apparent, to those skilled in this art, that all of theabove described organizations-which have been presented as exemplary orillustrative embodiments ot my present impi'ovements--possess certaincommon characteristcs of construction and operation, and have certainstructural and 'functional advantages, that serve to broadly distinguishthis improved type of elastic suspension gear from other previouslyknown supplemental spring suspension systems. lith the previousdisclosure as a guide these various distinguishing features ot' myinvention will be readily appreciated by engineers and others who arefamiliar with existent forms et vehicle spring` supports; and they willbe enabled to utilize these features-in whole or in part as may bedesired-in the production of any additional forms of structure that maybe particularly adapted to various moditications ot' chassis traineconstruction. I do not there- 'tore wish to limit the scope otapplication oit 1ny invention to the several exemplifications thereoiwhich lY have speciiically describet and I claim:

l. In ashocl absorber organiza 'tion ttor two relatively movablemembers, the combination ot a main spring', means tor preventiini` theretlexiug or negative ilexure oit the said springY beyond the lormimposed thereon by the normal load stress, and an elastic connectioninterposed between said main spring and one of the said members.

2. In an elastic support system for two relatively movable members, thecombination ot a main spring rigidly secured to one of sai-d members,means t'or positively7 limitinfr the retlexing or recoiling oi thisspring when it is relieved of a portion of the normal load stress, andother means for elastically connecting said spring with the other otsaid n'iovable members.

.in a shock absorber system for two relatively movable members, thecombination, ot a main leai spring rigidly secured to one ot the saidmembers, a supplemental suspension spring interposed between the mainspring and the other ot said members, and means for preventing theretlexing or negative bending' oli the said main spring when the saidmembers are separated beyond the normal position ot static equilibrium.

Ll. ln an elastic support system for vehicles the combination of' aprimary spring, a secondary spring arranged in series therewith, a leversuspension member conjoining said primary and secondary springs, andmeans tor limiting the angular movement oi' said lever member andthereby preventing the indexingv or reverse tleXure ot' the primarysprinjr when the normal or static load stress thereon is diminished.

5. n elastic suspension gear for vehicles which comprises a main leafvspring' rigidly secured to one oi" the vehicle members, a leverpivotally mounted on the same member and .llesibly coupled to the saidmain spring, a stop for limiting the angular movement of said .leverwith respect to said spring and said member and thereby preventing theretiexinyj of the latter beyond the form which it .es under normal load,and a secondaryv spring interposed between the lever and anotherrelatively movable vehicle member.

6. An elastic suspension system i'or two relatively movable chassismembers wiich comprises a primary spring' element rigidly mounted on oneot said members, means for limiting the reiiexing or negative tlexure otsaid primary spring on its mounting, a secondary sprinp' element mountedon the other of said members, and means for conjoining said primaryspring and said secondary spring' whereby the latter is adapted toelastically resist the movement ot said chassis members in eitherdirection lrom normal load position.

7. In a shock absorber organization i'or vehicles the combination oit amain spring rigidly molmted on one ol" the relatively movable chamembers, a lever-stop mechanism carried by this saine member and adaptedto limit the 'flexural inovement ot the main spring' with respectthereto. a supplemental spring carried by the other relatively movablechassis member, and means tor connecting the supplemental spring withsaid main spring', whereby any displacement oi the latter trom normal orstatic load position is elastically resisted by said supplementalspring'.

8. In an elastic suspension t'or vehicles. the combination of a mainspring rigidly niounted'zl'onfone of thei relatively movablevehicle#membersga substantially rigid lever pivotally connecteduivitli:they said spring .at

tivo points in tlieleng'tli thereof anda stop iffor limiting theflexural movement ,of the sprii'ig intermediate of its flexibleconnections with the said lever.A

9. An elastic suspension system compris,

ing a main leaf spring' member, a rigid lever tniember i'iii'otallyconnectedtherewith at one peint and flexibly coupled thereto at anotherpointin its .-leniijlli, a stop for limiting the angularA iin-ivenieiitVof tlicilever von its` pivotal moiintingrY and thereby limiting' thereflexing .i oi the said leaf spring when the load stress thereonfisdiminished, and-an elastic supporti for the free end of the said lever.

l0. In .an elastic4 suspension4 system for vehicles :the: combination fof ia .ma-in i springy supported on oiielof the relatively I'nowablechassis -members, a: supplemental spring mounted on: the other; oit saidmembers,-I

means. conjoininlgi the iiiainfspring 4and the supplemental.. springwhereby an increased flexure is imposedon the latter'zby any idisfplacement of the said members :from normal` load position,V and othermeans conjoining the niainwspringWiihiits cliassissupport wherel'iy thesaidmainispring is prevented lffroni reflexingivhen the normal loadstress fliereonii is: diminished by .rebound vor "sepiii ration of the:4chassis members beyondisaid normal position.

llfAv i spring suspension member which `comprises .a i volumetrically-elastic fluid con- `lSZN'Aspring suspension element which: comipriseslongitudinally eXpansi-ble vesselz having a plurality of radiallyspaced.flexible` side Wallspermanently connected in series with i eachotheruand .means v,for limitingfrthe` expansion. of said vessel when itis charged to a 1 predetermined fluid pressure.l

13.? A. fluid springxsupport Whicliiicom-f prises :a `volumetrically`variable container' having` 'plurality of flexible radially spaced1 andiseries-connected iside: Wall elements of l much greater' aggregatelength than :the container itself, fandvfmeans for `limiting-thelongitudinal oriendwise `movement of .each of the said flexibleziwalls.

14:. In a spring suspension member the combination of; a volumetricallyelastic metal vessel provided with a Iplurality l of seriesconnectedflexible side Walls radially spacedl to formnannular compartments, meansforV l5. 'In' a spring suspension-member :thef` .combination of a`:volui'iietrically elastic con-2 1 tamerf. provided` with 3 a pluralityyof exible f radiallyspaced-i andaseriesfcoimected `sideil Wallelements, and with relatively rigid A.endzftr Walls, means :for:limiting the! separationiof said end. iralls w ien the vessels-ischargedil with fluid to a -liiredetieiimined Aload i carrying: 5,capacity; and means;ffoiruhermetically ,Scali-.i1 ing saidvessel.aftersiicli':cliarging. i 752' 1G. A .vol-iimetrrically elastic-ves'sel--.comii prisinga plurality of-radiallywdispesed ani*longitudinally `flelxii'ile Wall elementaren, lon gitudinal-ly rigidtube winterposed i, ibetiveen;` successive 1W all -el einen ts, andimeansifor li er-.f' 801 ineticallyvconnecting-the .oppositei endsof'lsaid tube -to tllei adjacent ends of` sai'dfsucicessive .'yradia-lly: zseparated flexibles, Walls .zivherebyv lie :latter arenfconstrained toact inf? seriesarelation ivliei'i the .vessel expandseandf.zl5i

contracts.

17.' In 'a fluid pressiirespring support yfor tivo relatively 'lmovablevmembers i thei` colmi bination of a 4volumetrically#elasticacone:.tainerI having side wallsvofradially; cor-1905"?? riigated material,`means forsupporting;theix` sairl'container .on one ofthe saidmeinbersgf, other `rmeans: forioperatively connecting sai-dcontainerwvith thea u other Yof saidffmeinbersff whereby `.thecontainer: iand its fluid .contentsii95f will be volumetrically`compressed WhenitheV said members move toward each otherixandw meansfor .preventing va reverse i Iexp a-nsion movementzof the. container`:When the mem-.T bers `separate beyond normali'or` static Aload .100position. l.

18; A fluid` pressure springsupportifor-fi two rela-tively;A movableparts comprising the combination of a volumetrically *varia-ble'I imetali containerihavingaa plurality-of flexi 405* ble f. radiallyspaced; and series-connectediH side yWallsl and relatively rigidendqwalls, meansi for supportingbne `ofthe endzwallsi; on one of saidmov-able parte; .other means'i for operatively'connectingthe oppositeend H0" :Wallsto'f tlie-fvother;l of nsaid: movable; par-.tsl

whereby the flexible.: seriesconnectediisideg Walls are@ cooperativelyreduced in length?- and the end Walls moved towardv each other:ywheniithe: springv supported; parts.-are'rsub` 115 jected to increasedload,iand;a plurality lofi stops for limiting the expansioni movement'of-'the flexiblesidefwalls When the load stress on thesaidyparts isreducedfbelowfthe -v normal` value i y y `12.0

19.-A fluid pressure spring` support for vehicles q, which i comprisesthe combination of a ivolunietricalfly elast-ic container .havingcorrugated and longitudinally ,flexible side walls mounted on one offfthe relatively 125 movable chassis members a connective.. mechanism:conjoininggthe-` said container ivi-th the other ,of said memberswhereby the container i and its fluid: Econtents arevolunmetricallycompressedi Whenfthe chassisvlolf members are moved fromnormal load posi-- tion toward each other, and means for pneumaticallyresisting the rebound or separation of the said members beyond thenormal load positions.

20. In a fluid pressure spring suspension for two relatively movablemembers the combination of a volumetrically variable fluid containersupported on one of said members, means conjoining the other of saidmembers with one. end of the said container whereby the latter isvolumetrically compressed when the said members are forced toward eachother, means for damping or retarding the recoil or reflex movement ofthe compressed container when the members return toward normal vorstatic load position, and means for arresting any further expansion ofthe fluid pressure spring when said normal load position has beenreached.

2l. In a fluid spring support the combination of an hermetically sealedpressure chamber having rigid end walls and a plurality of radiallyspaced flexible side walls connected in series by rigid tubes interposedbetween the said walls, with means for limiting` the relativelongitudinal movement of each of the said rigid tubes and other meansfor limiting the separation or expansion of the end walls of the saidchamber.

22. A fluid pressure spring which comprises an hermetioally sealedelastic container, a metal spring confined therein and acting to expandsaid container, and means for limiting the said expansion movement.

23. A fluid pressure spring which comprises a voluinetrically elasticvessel having a plurality of flexible side walls connected in serieswith the opposing ends thereof, and a metal spring confined under aninitial tension between the said ends and exerting an expanding pressurethereon.

24. A fluid pressure spring which comprises an hermetically sealedvessel having corrugated metal side walls, and relatively rigid ends, ametal spring interposed between these ends and exerting an expandingpressure thereon, and stops for limiting t-he separation of the saidends by the expansive action of' the spring elements.

25. A fluid pressure spring which comprises a volumetrically variablecontainer having a plurality of flexible radially spaced and seriesconnected side walls hermetically joined to each other and to theopposing ends of the container, a coil spring interposed between theseends, and means for limiting the relative movement thereof in bothdirections.

26. A vehicle suspension spring which comprises a flexible hermeticallysealed vessel partially filled with liquid and changed to apredetermined pressure with an elastic fluid, a metal spring interposedbetween the relatively movable parts of the said flexible vessel andacting to hold said parts in expanded position, and means Yfor limitingthe expansion of the said metal spring.

27. A composite spring member which comprises a volumetrically elasticcontainer having substantially rigid heads and a plurality of radiallyspaced longitudinally flexible wall elements interposed between saidheads and connected in series with each other by rigid tubes interposedbetween the successive radially spaced walls, a metal spring elementalso interposed between the said heads, and means for lii'i'iiting therelative separation thereof'.

28. A composite spring member which comprises a hermetically sealedelastic vessel provided with substantially rigid end walls and withlongitudinally flexible side walls consisting of a plurality of'radially spaced series-connected metal bellows, stops for limiting therelative expansion movements of the said bellows, a metal springinterposed between the said rigid end walls, and stops for confiningsaid metal spring under a predetermned initial tension.

29. A composite spring` support for two relatively movable members whichcomprises a longitudinally flexible container having transverselycorrugated side walls the said container being partially filled withliquid and charged to a predetermined pressure with an elastic fluid, ametal spring interposed between the ends of' said longitudinallyflexible container, stops for limiting the expansion thereof, and meansconjoining the said ends with said relatively movable members wherebyany displacement of' the latter from normal position imposes anincreased compressive stress on one of the composite spring elements.

30. An air spring support for vehicle bodies which comprises anhermetically sealed longitudinally flexible container havingtransversely corrugated side walls the said container being partiallyfilled with a mobile liquid and charged with compressed air to apredetermined load carrying capacity, a metal spring' enclosed in thesaid container and confined at a predetern'iined initial tension betweenits ends, means for limiting the expansive movements of the chargedflexible container, means for attaching said container to one member ofthe vehicle chassis and other means conjoining said conainer withanother relatively movable member thereof whereby any displacement otlthe said members from normal load position will subject one of theelastic elements of the spring to increased compression.

3l. ln a composite spring suspension for two relatively movable members,a vessel having longitudinally lflexible side walls and reiatiyely rigid.end walls, means for charging said vessel with` an elastic fluid andconfining it therein atA a ,predetermined initial pressure, a metalspring interposed between therigid end walls, stops for limiting theexpansion or separation thereof, means. conjoining the said end wallswith the relatively movable memberswhereby any displacement o'l thelatter from normal position will iinpose an increased compression on oneof lthe composite spring elements, and other means for in'lposingapneumatic dan'iping action on the recoil or expansion moven'ient of theabnormally compressed Ispring elements.

32,. In a spring supportitoil vehicle bodies the combination of ahermetically sealed fluidcontainer having rigid ends` and longitudinallyflexible side` walls that comprise a pluralityof' `cmicentricallyarranged metal bellows connected' in series by intervening rigid tubes,stops for individually limiting. the relativelongitudinal movements of.the said sidewall elements, a metal spring interposed between. therigid ends of' the container, stopsffor limiting the expansion of thesaid spring, and other means for arresting the'compression movements ofthe entire assembly.

A spring suspension element which comprises a volumetrically elasticvessel having a plurality of longitudinally flexible side wallsfandmeans'for" holding said walls in nested and radially spaced relationshipwith each other.

34;. A fluid pressure. spring which comprises a volumetrcally variablecontainer having rigid ends and a plurality of longitudinally flexibleside walls connected in series with each other, and a. plurality ofradially engaged guide elements for maintaining said side walls insubstantially concentric relationship with the said rigid ends.

S5. A fluid pressure spring which comprises a volumetrically variablevessel having substantially rigid end walls and a plurality oflongitudinally flexible metal side walls disposed in radially spacedrelationship and connected in series by intervening metal tubes, andmeans for maintaining the assembled parts in said radial relationshipduring the expansive and eontractive movements of the flexible sidewalls.,

36. In a Huid pressure container the combination of' rigid headelements, a plurality of' radially disposed and flexible side wallelements interposed between said heads and hermetically connected inseries with each other by intervening rigid tubes, and a plurality of'radially engaged guides for maintaining said side wall elements againstlateral displacement.

37. In a spring suspension system for vehicles the combination of a mainspring, a supplemental spring, means for simultaneously imposing anincreased fiexural strain on bothV of said springs when the system issubjected to increased compression stress and other means forindependently arresting the reflex or expansion movement of' each springwhen it has returned to normal` load forni.

38.111 an elastic suspension systemY for vehicle bodies the combinationof a main spring, a supplenjiental spring, a lever `con'- joining saidsprings whereby the latter are subjected to an increased flexnre whenthe load stress thereon is abnormal y increased, means for damping orretarding the recoil or expansion of' the abnormally flexed springs asthe. increased load stress is. removed, and other means for positivelyarresting the reflex or expansionV movement of both springs beyond theirnormal, load form.v

39. In an elastic suspension system for two relatively movabe membersthe combination of' a main spring, a lever flexibly connected with this,springat two different points in its length, lever stop element adapted`to engage said sii-ing at a third point inthe length thereonasupplemental spring, means conjoining said lever with said sinapiementalspring whereby the latter is adapted to resist any displacementof thesaid 'iembers from normal or static-,load position,` and otherme-ansgfor damping-'or retarding the recoil or return movement of theparts to the said Vnormal position.A

40. In an elastic suspension system, the combination of a main spring, asupplemental spring cooperating in series therewith, a lever mechanismco'njoining said springs whereby the latter are concurrently subjectedto increased flexure when the system is compressed, means for limitingthe refiex or subnormal flexure of both springl when the system expands,and other means for imposing an elastic restraint on the expandingsystem.

41. An elastic suspension system com prising a main spring, asupplemental spring, means for coupling said springs in operative seriesrelationship whereby they are concurrently flexed when the system iscompressed` means for retarding the recoil of the flexed springs whenthe compressed system returns to its normal position of staticequilibrium, means for preventing the reflex movement of the saidsprings beyond their normally tensioned form, and other means for againsubjecting the supplemental spring to increased flexural strain when thesystem continues to expand beyond its normal position.

4Q. An elastic suspension system for vehicle bodies which comprises amain spring, a -lever flexibly connected therewith at a plurality ofpoints in the length thereof, a stop attached to said lever and adaptedto engage said spring at another point in its length, a supplementalspring mounted on the vehicle body, means eonjoining said lever withsaid supplemental spring whereby the latter is subjected to an increasedli'exural strain when the vehicle blody is moved in either directionfrom its normal or static load position, means for damping the recoil olthe abnormally tlexed supplemental spring, and other means forpositively arresting said recoil movement when the said spring hasreturned to its normal load form.

43. An elatic suspension system for vehicles which comprises a main leafspring, a supplemental fluid pressure spring, means for coupling saidsprings in operative series relationship whereby the leatlspring isincreasingly flexed and the fluid pressure spring is compressed when theelastically suspended parts are `forced toward each other, means forarresting the reflex movement of the leat spring when the said partsrebound or separate beyond normal load position, and other means foragain subjecting the supplemental spring to increased compression duringthis rebound movement.

44. In an elastic suspension system for vehicles the combination of amain spring, a supplemental fluid pressure spring, a lever mechanismconjoining said springs in operative series relationship whereby both ofthe said resilient suspension elements are subject-ed to a concurrentlyincreased tlexure or compression when the body and axle parts are forcedtoward each other, a stop For locking the main spring in fixed lecturalrelationship to the lever mechanism when the system rebounds or expandsbeyond normal load position, and an auxiliary connection between saidlever mechanism and one of the relatively movable vehicle memberswhereby the Huid pressure springis subjected to increased compressionduring such rebound or expansion movement.

45. In an elastic suspension system for vehicles the combination of amain leaf spring rigidly supported on one of the relatively movablychassis parts, a supplemental air spring mounted on the other of saidparts, means conjoining said main and supplemental springs in operativeseries relationship whereby both oit' these elements are positivelycompressed when the system is subjected to an abnormal load stress, stopmembers for locking the normally flexible portion of the main spring inlixed relation to its chassis support when the system rebounds orexpands beyond normal load position, and an auxiliary one way connectionconjoining said interloclied main spring and stop menibers with thesupplemental air spring whereby the later is compressed during theaforesaid rebound movement.

In testimony whereotl I have hereunto set my hand.

FRANK L. O. VVADSVORTH.

